A NIR laser induced self-healing PDMS/Gold nanoparticles conductive elastomer for wearable sensor.

Self-healing conductive elastomers have been widely used in smart electronic devices, such as wearable sensors. However, nano fillers hinder the flow of polymer segments, which make the development of conductive elastomer with rapid repair and high ductility a challenge. In this work, thioctic acid (TA) was grafted onto amino-modified polysiloxane (PDMS-NH2) by dehydration condensation of amino group and carboxyl group. By introducing gold nanoparticles, a dynamic network based on S-Au interaction was constructed. The dynamic gold cross-linking could effectively dissipate the energy exerted by external force and improve the extensibility of conductive elastomer. In addition, S-Au interaction had a good optothermal effect, so that the elastomer rapidly healed under NIR irradiation, and the repair efficiency reached 92%. We further evaluated the performance of the conductive elastomer as a strain sensor. The sample could accurately monitor the bending of human joints and small muscle state changes. This kind of self-healable conductive elastomer based on dynamic S-Au interaction has great potential in the fields of interpersonal interaction and health monitoring.